1. Field of the Invention
The present invention relates to a bicycle wheel, more particularly to a bicycle wheel with spokes that have end portions bent at a small angle to prevent breakage of the spokes.
2. Description of the Related Art
In U.S. Pat. No. 6,186,598, there is disclosed a bicycle wheel rim with an H-shaped cross-section. A plurality of hollow packing members are mounted on the wheel rim for reinforcing purposes. The packing members are formed with through holes aligned respectively with spoke mounting holes in the tire retaining walls of the wheel rim to permit installation of spokes on the wheel rim. The spokes have outer end portions mounted on the wheel rim and the packing members, and inner end portions to be mounted on a hub. The outer end portions of the spokes are generally bent by an angle greater than 90xc2x0. As such, the spokes are susceptible to breakage. The bicycle wheel thus requires a relatively large number of the spokes so as to reduce the stress applied to an individual spoke.
Therefore, the main object of the present invention is to provide a bicycle wheel with spokes that have end portions bent at a small angle to prevent breakage of the spokes.
Accordingly, the bicycle wheel of the present invention is adapted to be installed on a wheel axle, and includes a hub, a wheel rim, and a plurality of spokes. The hub is adapted to be mounted rotatably on the axle, and has left and right end portions which are opposite to each other along an axis of the axle. Each of the left and right end portions is formed with a set of spoke fastening holes which are arranged around the axis of the axle. The wheel rim is disposed around the hub. The wheel rim includes spaced-apart left and right annular tire retaining walls, each of which has a radial inner section proximate to the hub, a radial outer section distal to the hub, and an intermediate section between the radial inner and radial outer sections. The radial outer sections of the tire retaining walls are adapted for retaining a bicycle tire therebetween. The radial inner section of each of the tire retaining walls has a lateral inner surface confronting the radial inner section of another one of the tire retaining walls, and a lateral outer surface opposite to the lateral inner surface. The radial inner section of each of the tire retaining walls is formed with a set of spoke mounting holes, each of which extends through the lateral outer surface and the lateral inner surface of the radial inner section of a respective one of the tire retaining walls. The wheel rim further includes an annular base wall interconnecting the intermediate sections of the tire retaining walls. Each of the spokes has an inner end portion mounted on a respective one of the spoke fastening holes in the left and right end portions of the hub, and an outer end portion mounted on a respective one of the spoke mounting holes in the radial inner section of a respective one of the tire retaining walls. The outer end portion of each of the spokes includes an enlarged head abutting against the lateral outer surface of the radial inner section of a corresponding one of the tire retaining walls, an extending section connected to the enlarged head and received in the respective one of the spoke mounting holes, and a bending section connected to the extending section and disposed adjacent to the lateral inner surface of the radial inner section of the respective one of the tire retaining walls. The bending section is bent from the extending section, and extends from the extending section toward the inner end portion of the spoke.